1. Technical Field
The disclosure relates to an Inductively Coupled Plasma (ICP) emission spectrometer for analyzing elements (for example, trace impurity elements) contained in a solution sample.
2. Description of the Related Art
An ICP emission spectrometer atomizes or ionizes a solution sample for ICP emission spectroscopy by using inductively coupled plasma (ICP), and performs a spectroscopy analysis on atomic emission lines (spectral lines) emitted at that time so as to perform a quantitative analysis and a qualitative analysis on trace impurity elements. Then, a spectroscope used for the ICP emission spectrometer includes a sequential-type spectroscope which sequentially detects diffracted light of each wavelength and a multi-type spectroscope which simultaneously detects the diffracted light. An ICP emission spectrometer is known which can control a desired wavelength to be located at a position where the desired wavelength is incident on a detector, by driving a diffraction grating using the sequential-type spectroscope (refer to JP-A-S59-151027).
JP-A-S59-151027 illustrated in FIG. 5 discloses a sequential determination emission spectrometer in which light emitted from a light source 100 for emitting the light by exciting a sample is imaged by using a light condensing lens 101, the light transmitted through a light incident slit 102 is introduced into a grating 105 driven by a grating drive circuit 104 by using a collimator 103, the light diffracted by the grating 105 is imaged on a light emission slit 108 driven by a light emission slit drive circuit 107 by suing a camera mirror 106, the light received from the light emission slit 108 is converted into a current by using a detector 109, and an output current is converted into concentration by using a data processing circuit 110. According to this configuration, light intensity is not changed regardless of a position of the light emission slit 108, and there is no change in a refractive index depending on the wavelength. Accordingly, JP-A-S59-151027 discloses that excellent resolution is obtained since the light is exactly imaged on the light emission slit 108 by using the camera mirror 106.